


'S' is for Shape-Shifters

by lost_in_thyme_and_spacebars



Category: Star Trek: The Original Series
Genre: Blood and Gore, Gen, Horror, Mental Health Issues, Paranoia, Psychological Horror
Language: English
Status: Completed
Published: 2014-10-25
Updated: 2015-01-03
Packaged: 2018-02-22 14:11:41
Rating: Teen And Up Audiences
Warnings: Graphic Depictions Of Violence, Major Character Death
Chapters: 4
Words: 2,331
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/2510567
Author URL: https://archiveofourown.org/users/lost_in_thyme_and_spacebars/pseuds/lost_in_thyme_and_spacebars
Summary: <blockquote class="userstuff">
              <p>Either Bones is overworked, or those are not his friends.</p>
            </blockquote>





	1. Chapter 1

**Author's Note:**

> Please see the end for plot specific warnings. I don't want to spoil anything but I'd like to not cause any (unwanted) distress.  
> I hope you enjoy the story!  
> Written for Prompt: Shapechangers  
> Slight Edit: 28/10/2014

He had heard of the condition before, but never encountered it. Capgras syndrome. We haven’t left the ship in weeks, McCoy thought to himself, it must be the stress getting to me. Deciding to take advantage of the next shore leave, he returned to his work, hyper-aware of the presence of the ‘Nurse Chapel’ shaped intruder behind him.

Knowing what must be occurring should have, logically, made him feel better, but as he walked through the corridors the information provided little comfort. He quickened his pace, wanting to return to his quarters and the safety they represented as soon as humanly possible.

‘Bones, I have the best idea for next leave. I know this café where the women are so…’

‘Doctor McCoy, I have some documents for you to sign as soon as possible regarding the order of…’

‘May I suggest, Doctor, that you pay more attention to your surroundings.’ The words were as stiff and formal as the person whose body he had just collided with. Looking up into the eyes of ‘Spock’, he couldn’t even spit out one of his usual comebacks – not even a half-arsed insult. That creature in front of him wasn’t the man he knew. 

Spock looked exactly as he always had done. His mannerisms were the same, as was his composure and that annoying quirk of the eyebrow that he had never quite managed to imitate (not that he had tried, mind you. Not even once). But this wasn’t the hobgoblin he knew and… well, didn’t entirely hate. In fact, he realised with a growing degree of hopelessness that he would give anything to have his Spock back.

Without a word, he turned and opened the door to his sanctuary, feeling the gaze that was undoubtedly trained on his back. The doors closed behind him, and McCoy let out the breath that he had subconsciously been holding.

These were his friends. They had to be. It was just paranoia, or a delusion. He was sick, that was all. Taking the hypo of sleeping draught that he kept by the bed, he pressed it to his skin. Tomorrow this will all seem like a bad dream.

It didn’t. The imposters even had the gall to look concerned when he passed. This wouldn’t do. He took a detour into the mess hall on his way to sickbay, and began his work with due commitment. The blade in his pocket made him feel better, even if only by a little. He wouldn’t be replaced, not like they had been.

He wasn’t quite sure what triggered it in the end. Maybe it had been the brush of ‘Jim’s hand against his as the man struck up his normal banter. That skin didn’t feel right. It wasn’t human. It wasn’t Jim. When he turned to look, he finally saw it. Grasping the knife, he thrust the blade deep into its hand, pinning it to the table his ‘friend’ had been sitting on. The sound that came from its mouth was harsh and furious and full of rage. The disbelief in its eyes didn’t fool him for one second. That wasn’t Jim.

Running from the room, still clutching his weapon, he made a break for the escape pods. Maybe he would be able to get to safety. The blood ran over his fingers, thick, red and hot. As he ran, the blade shifted in his grip and the edge bit into his fingers. He stopped. His blood should be red, too, shouldn’t it? At the sound of approaching footsteps he whirled around and sliced the man-that-had-once-been-Sulu across the torso, his hearts pounding loudly in his head as panic set in. His hands were never that large before, were they? The fog that had overtaken his brain for the last month finally cleared, and a twisted grin broke across his features. Of course, the memory overwrite had been necessary to imitate the correct behaviour, to make them believe their CMO was still alive. No-one would have believed if he himself had not believed. He hoisted the knife and strolled leisurely towards the bridge as the last vestiges of his false identity faded. The rest of his men would need bodies to copy, and it was so much easier to do so when they were still. He would provide all they needed and more.

The Federation was going down.


	2. Chapter 2

Jim swore to himself. What the hell had gotten into Bones? Grabbing a handful of bandages, he ran from the room. Wrapping the material tightly around the broken flesh he looked wildly around for any signs of movement. A deep red was rapidly saturating the gauze, turning his stomach. He wasn’t sure whether the dizziness was from shock, disgust or simple blood loss. I could use a doctor, he thought with a slightly hysterical sound halfway between a laugh and a sob.

Hearing a shout, he ran towards the source, stopping dead in his tracks as he took in the still form of his helmsman. His torso was slashed from shoulder to hip and no-one would have been able to tell that his shirt was once the same bright gold as Jim’s own. He knelt down in the mess, feeling for a pulse at the neck, all the while trying to ignore the sticky warmth seeping through the knees of his trousers. There was nothing.

Pushing back the nausea, he got to his feet. Smeared footprints led away from the body, as if his friend – no, he thought, the killer – hadn’t been quite so steady either. This jolted him from his stupor. Maybe there was a chance of heading him off before anyone else got hurt. 

~*~

When the turbo-lift doors opened onto the bridge, there was no immediate reaction. Commander Spock turned from his station, expecting the return of his Captain. He was halfway through his greeting when the words died on his lips.

McCoy had been acting strangely for a while to be sure, he knew this, but the figure in front of him was jarring to behold. The smile was wrong, for a start. It was feral, twisted and malicious. Had that been all, Mr Spock might have assumed that the good doctor had finally broken from the stress – something that he had been advising him to address as recently as yesterday. The blood, however, pointed to something beyond that.

It was splattered diagonally across the normally pristine blue uniform shirt, its shape indicating that the impact of the liquid had been sudden and violent. This contrasted with the blood that was currently dripping from the sickeningly pale hand; the hand that was clasped around an equally coated blade. 

There was no more time for thought. Their eyes met and the smile grew bigger. If Spock had been prone to exaggeration, he would have said that it threatened to split McCoy’s face in two. The man approached unthinkably fast, his feet making no sound on the floor. Were they even touching the ground? He raised his head and found himself almost nose to nose with the man he had thought he’d known. Those eyes weren’t blue anymore. There was no breath ghosting along his skin. Sudden pain shot through his body and his life flowed thick and warm from the laceration across his jugular. As his vision dimmed, the stillness that had enveloped the bridge shattered. Flashes of gold, red and blue merged with the greys of the room. He was gone before he hit the floor.

~*~

Now this is what I call a good time, it thought as the Vulcan collapsed to the floor. The warmth made it shudder in delight and it luxuriated in the sensation, allowing its eyes to close and tilting its head back, feeling the tension leave the muscles that had still been suffering from their brief stint in human form. Nothing was worse than the feeling of cooled blood against skin, and these clothes had begun to feel, well, clammy for want of a better word.  
The copper tang of the green blood filled the air, and the bloodlust singing in its veins grew louder. The others had begun to turn around just before the knife had sliced through the delicate flesh of their comrade, and it relished the fear that the show had caused. It discarded the final remains of the shape it had worn, and the fear grew greater. Dropping the now redundant metal, it turned to its audience.

It was so much easier now, it thought as it jumped over the railing towards its next victim. Its fingers, returned to their natural shape, were longer, thinner and more sinewy than a human’s, and they carved through the hot flesh easily. It made sure not to cause an excessive amount of damage – after all, they bodies had to be recognisable if they were to be of use. Still, it thought as it tore through the flesh of a young human already clothed in red, that didn’t mean that it wouldn’t be fun. Maybe it would let one or two escape. The chase was always the most thrilling part.


	3. Chapter 3

The second the doors to the bridge opened, Jim knew he was too late. At first glance, it merely seemed empty – a bad sign in itself. Turning to where his first officer would have stood, his already tenuous grip on the world snapped. 

He staggered over to the form, his mind whirling. Falling to his knees, he rolled the body over. He had to be sure. Looking at the face, he could have almost been asleep. He gently moved the hair back to its normal immaculate position, ignoring the cooling puddle of green blood seeping through his trousers and mixing with the red. The neck, exposed in more ways than one, was the hardest part to look at. The cut, whilst precise, had been powerful enough to create a deep incision. There would have been no chance to scream, as the vocal cords would have been severed instantly. He couldn’t even imagine how terrifying that would be. Pressing a soft kiss to his friend’s forehead, he stood again, feeling himself detaching from the situation as he pulled away.

The rest of the Bridge was in a similar state, he found, now that he could see the floor clearly. There was so much blood, yet so little sign of a struggle. The killer must have been upon them before they had fully registered what was happening. Seeing his crew – no, his family – lying there unmoving would have broken his heart had it not already become numb. 

The creature had left, probably to go after the rest of his ship. He might be able to reach some of them before it, but then what? Whatever had done this would cut through him in a moment. What could he do against something so dangerous?

A glint in the corner of his eye caught his attention. A single knife, the same one that had pierced his hand what seemed like an age ago, lay on the floor. He picked it up, barely registering the blood that oozed onto his skin from the blade. To be honest, there was very little of him that wasn’t already tainted in that way.

He walked into the turbolift, and directed it to engineering. Scotty might still be alive. As it slowed to a halt and the doors opened, he let out a breath he hadn’t known he was holding. No blood. No yelling. He might be in time.

‘I don’t think so, Jim…’

No. Not that voice. Please, not that voice. The soft southern lilt echoed gently through the hall. The amusement in it made him relax automatically until reality kicked in. That was not his friend anymore. 

‘Why Jim, you look tired. Rough day? Maybe you should stop by the medbay. I’m sure there’s something I can do.’

‘Stop it!’ he yelled, moving his head frantically from right to left. The voice was coming from all directions.

‘Now, now. What would our dear Mr. Spock say if he saw you behaving in such an illogical manner, hmmm?’

Images flashed through his mind, causing him to claw at his head. He wanted them gone. He couldn’t deal with this. A soft pressure fluttered along his shoulders, and he turned. It happened again. He span around and around, trying to catch the creature in action. 

‘Dammit Jim,’ the voice muttered in his ear before changing to a snarl, ‘I thought you would put up more of a fight’. He felt something slide across his throat, followed by an unbearable heat flowing down his body. As he fell backwards, he saw a distorted shape on the ceiling. One of its arms were stretched towards him, its claws slowly dripping his blood slowly back onto him as he hit the ground. One, two, three… and then nothing.


	4. 3 weeks later

‘It is good to see you again, Captain’

‘It is an honour to have you aboard, Admiral’

‘It’s a bit cold here isn’t it? Are the environmental controls not functioning?’

‘It is simply bad timing. They stopped working this morning, but I can assure you our engineers are working on it full time. They should be up and running again soon.’

‘Is that why you are wearing scarves?’

‘I am sorry that it is not very formal, but when dealing with such an important mission I cannot afford for my crew to get ill.’

‘That is true. Well, come along then. The ambassadors are waiting, and the sooner we get this sorted out, the sooner we can move forward.’

‘I couldn’t agree more, Admiral. Commander Spock, Doctor McCoy – let’s go.’

As they disembarked, Jim allowed himself to smile. He ran his fingers along the scarf, gently brushing the scar underneath. He caught the eyes of his companions, whose eyes were full of the same anticipation as he imagined his own were. All the planning would be worth it. This was going to be a very good day. Blood would run.

**Author's Note:**

> Contains Implied Mental Illness, Violence, Psychological Distress, Paranoia and Deception.


End file.
